1. Technical Field
The present disclosure relates to a waste ink tank that stores the waste ink ejected from an inkjet head when flushing the inkjet head, and to an inkjet printer that uses the waste ink tank.
2. Related Art
Inkjet printers regularly execute a flushing operation to prevent the ink nozzles from becoming clogged due to the ink increasing in viscosity. The inkjet head is set to a maintenance position opposite a head cap, and ink droplets are then ejected from the inkjet head into the head cap during the flushing operation. The ink ejected into the head cap is recovered as waste ink and stored in a waste ink tank.
JP-A-2010-137550 describes an ink cartridge that has an ink tank and a waste ink tank. The waste ink tank has a case that stores the waste ink, and the case has a waste ink inlet through which waste ink stored in the head cap is input to the case, and a vent from which air is removed from the case when waste ink is input. The case is thin and flat to minimize the space occupied by the waste ink tank when the ink cartridge is installed in the inkjet printer.
Some waste ink tanks have a sponge inside the case to absorb the waste ink. The size of the sponge must be increased in such waste ink tanks in order to absorb a sufficient volume of waste ink. However, because the waste ink tank is typically thin as described in JP-A-2010-137550, the strength of the case can be weakened as a result of increasing the size of the sponge.
Ribs could be disposed inside the case to improve the strength of the case. If ribs are provided, however, the ribs must not interfere with penetration of the waste ink to the sponge. Furthermore, because waste ink will spill from the waste ink inlet if air inside the case is not appropriately discharged from the air vent so that the air is steadily replaced by the waste ink, the ribs must also not block the air path to the air vent inside the case.